Utilize este identificador para referenciar este registo: http://hdl.handle.net/1822/35930

TítuloCarbonation resistance of high volume fly ash concrete
Autor(es)Reis, Rui
Malheiro, Raphaele Lira Meireles Castro
Camões, Aires
Ribeiro, Manuel
Palavras-chaveCarbonation
Sustainability
Durability
Fly ash
Data2015
EditoraTrans Tech Publications
RevistaKey engineering materials
CitaçãoReis, R., Malheiro, R., Camões, A., & Ribeiro, M. (2015) Carbonation resistance of high volume fly ash concrete. Vol. 634. Key Engineering Materials (pp. 288-299).
Resumo(s)The cement industry is responsible for a large part of the global environmental problems: is the largest consumer of natural resources; the most responsible for the emission of greenhouse gases, including about 1.8 Gt of CO2; and requires huge amounts of energy, corresponding to between 12 and 15% of industrial energy use. The cement is also not used in the most appropriate manner, since 40% of the consumption of concrete is due to the renovation and repair of buildings, making concrete structures inefficient because its durability is relatively low. However, in the future, concrete can and should evolve in order to improve its eco-efficiency, with a smaller amount of cement in its composition, replacing it with high quantities of mineral additions, particularly fly ash. Nevertheless, current technology may not allow this type of concrete to be very efficient, because its long-term durability may be compromised. In fact, with increasing dosage of pozzolanic mineral additions, alkali paste components are consumed in the reaction leaving it vulnerable to concrete carbonation which may compromise the passivation layer needed for steel rebar protection against corrosion. This article explores a promising approach to mitigate this problem, which consists in the careful addition of hydrated lime in the concrete composition, highlighting the synergy of its components, significantly enhancing its carbonation resistance. It is proposed, therefore, to manufacture a concrete with high volume of fly ash, low cement content and high service life period: an efficient and sustainable concrete. In this context, an experimental campaign was developed with the aim of characterization of pastes behavior with high fly ash content, in particular with respect to its durability. The results will be presented and properly analyzed.
TipoconferencePaper
Descrição"Chapter 2: Materials and Residues"
URIhttp://hdl.handle.net/1822/35930
DOI10.4028/www.scientific.net/KEM.634.288
ISSN1662-9795
Arbitragem científicayes
AcessoopenAccess
Aparece nas coleções:C-TAC - Artigos em Revistas Internacionais

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